Process Outlook Email Attachments & Embedded Messages in C#

Email attachments are files that are sent along with an email message, allowing users to share documents, images, videos, or any other digital content. Handling email attachments efficiently is a crucial aspect of modern communication systems, and for C# developers seeking a robust solution to manage them seamlessly within their applications.

C# .NET API to Manage Email Attachments

To process email attachments, we will use Aspose.Email for .NET, a powerful and comprehensive API designed for C# developers to work with email messages and various related tasks within their .NET applications. It provides a wide range of functionalities for creating, processing, converting, and managing messages, making it a valuable tool for businesses and developers who need to integrate email capabilities into their software applications. To leverage the power of the API, download its DLL or install it from NuGet.

Adding Regular Attachments

Regular attachments are standalone files that are included with an email message, typically displayed as separate icons or links within the body.

Email Attachment Example - Regular Attachment

Aspose.Email intuitive API allows you to add a regular attachment to a message in just a few lines of code. With the steps and a code sample below, you will create a sample email message (MSG) and add a file attachment (“document.pdf”) to it using the MapiMessage class in C#:

  1. Create or load a MapiMessage.
  2. Read the contents of the “document.pdf” to a byte array.
  3. Add the attachment with name (“document.pdf”) and the data to the Attachments collection of the message.

Adding Inline Attachments

Inline attachments are intended to be displayed within the body of the email message itself. This is often used to embed images or other media directly into the email content, allowing the recipient to view the content without needing to open a separate attachment.

Email Attachment Example - Inline Attachment

The image in the message content is an inline attachment. The Aspose.Email API allows to check if an attachment is inline before performing other manipulations with it, and the code sample below demonstrates how to perform this task.

  1. Load the email message from the file using the MapiMessage.Load() method.
  2. Iterate through its attachments collection.
  3. For each attachment in the collection, print out their display names along with a boolean values indicating whether they are inline or regular.

Adding Reference Attachments

Reference attachments do not contain the actual file content within the email message. Instead, they include links to external resources, such as images hosted on a web server. When the recipient opens the email, their client or web browser fetches these resources from the specified URLs to display the content. Thus, a user can send it with a link to a file stored in Google Drive. Instead of attaching the document directly to the message, you can create a link attachment that links to the file on Google Drive.

Email Attachment Example - Reference Attachment

The code sample below demonstrates how to create a message with a reference attachment:

  1. Create or load a MapiMessage object.
  2. Add a reference attachment to the message using the MapiAttachmentCollection.Add method, providing the file name, file URL, folder URL, and provider name.
  3. Set the permission type for the attachment using MapiAttachment.SetProperty method to specify who can edit it.
  4. Optionally, you can set additional properties, such as original permission type, whether the attachment is a folder, provider endpoint URL, preview URL, and thumbnail URL.
  5. Save the message to a file using the Save method.

Adding Embedded Messages

Embedded messages are those included or nested within another email message. They can contain their own content, attachments, and metadata, and they are typically encapsulated within the body or as attachments of the parent message.

This concept is commonly used in scenarios such as forwarding or replying to emails, where the original message is included as part of the new message. In such cases, the original message becomes an embedded one within the new message’s body preserving its own content, including sender, recipients, subject. This feature is fundamental to email communication and enables users to maintain a coherent conversation thread while exchanging messages.

Embedded Message Example

Aspose.Email provides components for this feature implementation. The following code sample with steps demonstrates how to add an embedded object to an email message:

  1. Create an instance of the MapiMessage class.
  2. Load the existing message from the file using the MapiMessage.Load() method.
  3. Add the loaded message as an attachment to the previously created one. Use the MapiAttachmentCollection.Add method for this purpose.

Saving all Attachments to MSG as Separate Files

The code sample below will show you how to load an email message from a file and save each individual attachment from the message into a separate file with its original file name.

  1. Create an instance of the MapiMessage class.
  2. Iterate through the attachments collection of the loaded message.
  3. For each attachment, save it as a separate file using the Save method, ensuring that each attachment is saved with its original file name.

Conclusion

In this article, we’ve explored the practical implementation of adding different kinds of attachments and embedded objects to email messages, saving attachments to separate files in C#, providing concise code samples to illustrate the processes. Aspose.Email for .NET emerges as a versatile solution empowering developers to efficiently manage email attachments and enhance communication tasks within their applications, thus ensuring a coherent and seamless experience for end-users.

Free resources:

  • support forum to ask questions, seek assistance, and engage with the community to resolve issues or gain insights into using the library effectively
  • extensive documentation that comprehensively covers various aspects of the library’s functionality with access to API references, tutorials, code examples, and best practices
  • informative blog covering a wide range of topics related to email management, attachment handling, and other relevant subjects with insights, tips, and updates on the latest features and developments within the Aspose.Email ecosystem
  • free apps designed to enhance email management and productivity for users across various platforms

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